Pile or pile core



Dec. 7 1926. v

o. STERN PILE- OR PILE CORE Filed 001;. 12. 1925 1.7. Siam Patented Dec.7, 1926.

UNITED sra'rss 1 1,609,670 PATENT OFFICE.

OT'IOKAR STERN, OIE VIENNA, AUSTRIA.

FILE OR PILE CORE.

Application filed October 12, 1925, Serial No. 62,202, and. in AustriaOctober 9, 1924.

In most cases dealing with the withdrawal of driving piles, theemployment of very great pulling forces by means of very complicated,time absorbing and expensive devices is indispensable. Moreover in thedriving-in of sheet metal tubes by means of pile cores under certainconditions such a great adhesion of the tube to the pile core takesplace that during the withdrawal of the latter the driven-in sheet metaltube is liable to be lifted, and in some cases even the entirewithdrawal of the sheet metal tube together with the pile core takesplace. The object of the present invention is to avoid these drawbacks.

According to the invention a pile or pile core is provided with a shoelongitudinally movable relatively thereto and so attached as to beadapted to form a support for means exerting pressure on the piletoinitiate the withdrawal of the same when desired. The invention mayconveniently be carried into effect by rotatably mounting the shoe onthe end of a screw-threaded spindle engaging by its threaded portion ina corresponding nut portion on the pile.v

By this construction it is possible when the pile driving is effected,to initiate the removal of the pile by rotating the said spindle toexert pressure on the pile by the cooperation of the spindle and nut,the shoe acting as a support for the said spindle during this operation.The most difiicult part of the pile withdrawal may thus be easilyeffected.

In order that the invention may be more readily understood referencewill now bespindle B is mounted axially within the pilev or pile core.The upper end of said spindle at the head of the pile, is so formed thatstrong forces may be exerted for rotating the spindle by means of asuitable tool. In the example shown a square-shaped end B is provided onthe spindle.

The lower end of'the said spindle B is provided with a flange or collarA. This externally screw-threaded annular member D, which is pushed overthe spindle B and screwed into the'screw-threaded recess E. Steel ballsare preferably placed below it as indicated in Fig. l of the drawing,but obviously the free rotation of the collar may be effected by othermeans, such as by spherically shaping the lower surface A of the collaras shown in Fig. 2.

lVhereas the connection of the spindle B with the pileshoe S is effectedonly by means of the collar A, the connection of the spindle. with, thepile or pile core P is effected by the engagement of a screw thread onthe spindle in a nut or central member M at the lower end of the pile orpile core A sliding or telescopic connection can be provided between the.shoe S and the pile or pile core P by the arrangement of a sleeve H,which may either be secured to the lower portion of the pile as shown,or to the upper portion of the pile shoe in such a manner that theprojectingend of said sleeve H surrounds the end of the other member towhich it is not secured. The annular face G of the pile-shoe serves fortaking along the sheet-metal tubes during the driving-in of the pile orpile-core.

The working of the devices described 'aboveafter the'pile or pile core,with its shoe S raised, i. c. with its screw spindle B entirely screwedupwards, has been drivon or brought into its final position (Fig. 2) bypressure, driving, flushing or in any other convenient manner-consistsin rotating the spindle B in a clockwise direction, whereby the saidspindle B is screwed out downwardly from its nut M in the pile or pilecore P, whereby the bottom face F of the pile is lifted off the top faceof the pile-shoe, thereby pressing the shoe S and pile P apart.According to the relative resistance of these 'twoparts either the shoewill be forced down or the pile raised, or possibly they might both bedisplaced, in opposite directions.

The overcoming of the resisting forces acting upon the surface of thepile can usually be obtained, under most ground conditions, after moreor less strong forcing downwards of the shoe, if the length ofthetln'ead on the spindle and its nut M are sutiicient, thus fulfillingthe purpose of the present invention, that is to say, effecting thefirst lift by the pressing upwards.

of the pile. the most difiicult stage of pile withdrawal. is

The space created between the pile and shoe during this upwardmovementof the pile l? is closed by the projecting length ofthe sleeve-H,thereby preventing the entry of undesirable matter between the twoparts.

The further withdrawal of the pile together with the shoe hanging'on:its spindle may he elli'ected merely by-nioans of a hauling ropeafterthe pile has been loosened sufficiently by being lifted to theextent of about the length of thescrewed portion of the spindle B.

Afterwithdrawal. the pile again made ready for action by bringingthe topface of the shoe into contact with the: bottom face of the pile, byscrewing down the pile or pile corearound the stationarily held spindle,or by screwing up the spindle iir'case the pile or pilecore is heldstationary.

The present invention contains the followlng progressive featuresandudvantages as compared with known .pile raising methods and devices.

No separate lifting devices are necessary when employing the shoe forovercoming the generally very considerable forces acting on the surfaceof the pile to resist its withdrawal. The lifting power necessary issupplied by a rotary motion of the spindle, which may easily be effectedunder all conditions. and the spindle engages the pile not undertension. in eontradistinction to hitherto known methods. butunderupwardly directed pressure. The raising work of the shoe is independentof the compressibility of the ground surface which in pile driving isusuallyvery great and disadvantageous for the supporting of winches andother hoisting devices. The employment of the shoe prevents an injury toordestrnction of the bore hole or shaft walls or of the bottom of theshaft, which may happen in the case of stepwise lifting, or by thecommon method of rotating-andtwisting the pile. As soon as the shoe isput in action when a metal tube has been driven in the ground the pilecore is gradually separated from its enveloping sleeve, which is notsubjected to any upwardly directed tensional forces; so that not only aloosening, but rather a further; favourably acting, downwardly directedtension is imparted thereto. This latter action is dueto the fact' that'the lifting of the pile'core has notbeenelfected bytension, butby anupwardly directed pressure, supported by theshoe, sothat the shoe andthe enveloping sleeves carried with the shoe. are heldstationary intheir driven-in position or are evenwpushed' down still further.

Having now particularly described and ascertained the nature of my saidinvention and to be performed, l declarethatwhat I claim is 1. Incombination; pile cora -a shoemovable ion itudinally relatively. to thecore, and means supported by the shoevforv exerting pressure on the pilecore, to initiate the withdrawal of said core.

2-. In combination; a :pile core, a shoe 1novable longitudinally to saidcore,a spindle rotatahly mounted in the shoe having a threaded portionthereon, and meansonthe pile core engaging" the threaded portion of thespindle, whereby, inciclentto rotation of the latter pressure is exertedon the pile core.

3. An arrangementias claimed in claim 2 characterizedby the provision ofa flange on'the spindlerotatably mounted in a recess in the shoe.

l. An arrangement asclaimed in claiin l characterized by the provisionof means closing :the space between the pile core and the shoe when thelatter are separated.

An: arrangementas claimed in claim. 2 characterized by the provision ofmeansclosing: the space between the pile core and the shoe when thelatterare separated.

In testimony whereof I aflix my signature;

OTTOKAR STERN;

